Lincoln Electric Tandem MIG Torch Operating instructions

Brand: Lincoln Electric

Model: Tandem MIG Torch

Category: Welding System

Type: Operating instructions

Tandem MIG Torch

OPERATOR’S MANUAL

IM666-A

February, 2005

Safety Depends on You

Lincoln arc welding and cutting

equipment is designed and built

with safety in mind. However, your

overall safety can be increased by

proper installation ... and thought-

ful operation on your part. DO

NOT INSTALL, OPERATE OR

REPAIR THIS EQUIPMENT

WITHOUT READING THIS

MANUAL AND THE SAFETY

PRECAUTIONS CONTAINED

THROUGHOUT. And, most

importantly, think before you act

and be careful.

G3494-2, 3, 4, 5, 6

G3494-2A, 3A, 4A, 5A, 6A

• Sales and Service through Subsidiaries and Distributors Worldwide •

Cleveland, Ohio 44117-1199 U.S.A. TEL: 216.481.8100 FAX: 216.486.1751 WEB SITE: www.lincolnelectric.com

• World's Leader in Welding and Cutting Products •

FOR ENGINE

powered equipment.

1.a. Turn the engine off before troubleshooting and maintenance

work unless the maintenance work requires it to be running.

____________________________________________________

1.b. Operate engines in open, well-ventilated

areas or vent the engine exhaust fumes

outdoors.

____________________________________________________

1.c. Do not add the fuel near an open flame

welding arc or when the engine is running.

Stop the engine and allow it to cool before

refueling to prevent spilled fuel from vaporiz-

ing on contact with hot engine parts and

igniting. Do not spill fuel when filling tank. If

fuel is spilled, wipe it up and do not start

engine until fumes have been eliminated.

____________________________________________________

1.d. Keep all equipment safety guards, covers and devices in

position and in good repair.Keep hands, hair, clothing and

tools away from V-belts, gears, fans and all other moving

parts when starting, operating or repairing equipment.

____________________________________________________

1.e. In some cases it may be necessary to remove safety

guards to perform required maintenance. Remove

guards only when necessary and replace them when the

maintenance requiring their removal is complete.

Always use the greatest care when working near moving

parts.

___________________________________________________

1.f. Do not put your hands near the engine fan.

Do not attempt to override the governor or

idler by pushing on the throttle control rods

while the engine is running.

___________________________________________________

1.g. To prevent accidentally starting gasoline engines while

turning the engine or welding generator during maintenance

work, disconnect the spark plug wires, distributor cap or

magneto wire as appropriate.

SAFETY

ARC WELDING CAN BE HAZARDOUS. PROTECT YOURSELF AND OTHERS FROM POSSIBLE SERIOUS INJURY OR DEATH.

KEEP CHILDREN AWAY. PACEMAKER WEARERS SHOULD CONSULT WITH THEIR DOCTOR BEFORE OPERATING.

Read and understand the following safety highlights. For additional safety information, it is strongly recommended that you

purchase a copy of “Safety in Welding & Cutting - ANSI Standard Z49.1” from the American Welding Society, P.O. Box

351040, Miami, Florida 33135 or CSA Standard W117.2-1974. A Free copy of “Arc Welding Safety” booklet E205 is available

from the Lincoln Electric Company, 22801 St. Clair Avenue, Cleveland, Ohio 44117-1199.

BE SURE THAT ALL INSTALLATION, OPERATION, MAINTENANCE AND REPAIR PROCEDURES ARE

PERFORMED ONLY BY QUALIFIED INDIVIDUALS.

WARNING

Mar ‘95

ELECTRIC AND

MAGNETIC FIELDS

may be dangerous

2.a. Electric current flowing through any conductor causes

localized Electric and Magnetic Fields (EMF). Welding

current creates EMF fields around welding cables and

welding machines

2.b. EMF fields may interfere with some pacemakers, and

welders having a pacemaker should consult their physician

before welding.

2.c. Exposure to EMF fields in welding may have other health

effects which are now not known.

2.d. All welders should use the following procedures in order to

minimize exposure to EMF fields from the welding circuit:

2.d.1.

Route the electrode and work cables together - Secure

them with tape when possible.

2.d.2. Never coil the electrode lead around your body.

2.d.3. Do not place your body between the electrode and

work cables. If the electrode cable is on your right

side, the work cable should also be on your right side.

2.d.4. Connect the work cable to the workpiece as close as

possible to the area being welded.

2.d.5. Do not work next to welding power source.

1.h. To avoid scalding, do not remove the

radiator pressure cap when the engine is

hot.

CALIFORNIA PROPOSITION 65 WARNINGS

Diesel engine exhaust and some of its constituents

are known to the State of California to cause can-

cer, birth defects, and other reproductive harm.

The engine exhaust from this product contains

chemicals known to the State of California to cause

cancer, birth defects, or other reproductive harm.

The Above For Diesel Engines

The Above For Gasoline Engines

SAFETY

ARC RAYS can burn.

4.a. Use a shield with the proper filter and cover

plates to protect your eyes from sparks and

the rays of the arc when welding or observing

open arc welding. Headshield and filter lens

should conform to ANSI Z87. I standards.

4.b. Use suitable clothing made from durable flame-resistant

material to protect your skin and that of your helpers from

the arc rays.

4.c. Protect other nearby personnel with suitable, non-flammable

screening and/or warn them not to watch the arc nor expose

themselves to the arc rays or to hot spatter or metal.

ELECTRIC SHOCK can

kill.

3.a. The electrode and work (or ground) circuits

are electrically “hot” when the welder is on.

Do not touch these “hot” parts with your bare

skin or wet clothing. Wear dry, hole-free

gloves to insulate hands.

3.b. Insulate yourself from work and ground using dry insulation.

Make certain the insulation is large enough to cover your full

area of physical contact with work and ground.

In addition to the normal safety precautions, if welding

must be performed under electrically hazardous

conditions (in damp locations or while wearing wet

clothing; on metal structures such as floors, gratings or

scaffolds; when in cramped positions such as sitting,

kneeling or lying, if there is a high risk of unavoidable or

accidental contact with the workpiece or ground) use

the following equipment:

• Semiautomatic DC Constant Voltage (Wire) Welder.

• DC Manual (Stick) Welder.

• AC Welder with Reduced Voltage Control.

3.c. In semiautomatic or automatic wire welding, the electrode,

electrode reel, welding head, nozzle or semiautomatic

welding gun are also electrically “hot”.

3.d. Always be sure the work cable makes a good electrical

connection with the metal being welded. The connection

should be as close as possible to the area being welded.

3.e. Ground the work or metal to be welded to a good electrical

(earth) ground.

3.f.

Maintain the electrode holder, work clamp, welding cable and

welding machine in good, safe operating condition. Replace

damaged insulation.

3.g. Never dip the electrode in water for cooling.

3.h. Never simultaneously touch electrically “hot” parts of

electrode holders connected to two welders because voltage

between the two can be the total of the open circuit voltage

of both welders.

3.i. When working above floor level, use a safety belt to protect

yourself from a fall should you get a shock.

3.j. Also see Items 6.c. and 8.

FUMES AND GASES

can be dangerous.

5.a. Welding may produce fumes and gases

hazardous to health. Avoid breathing these

fumes and gases.When welding, keep

your head out of the fume. Use enough

ventilation and/or exhaust at the arc to keep

fumes and gases away from the breathing zone. When

welding with electrodes which require special

ventilation such as stainless or hard facing (see

instructions on container or MSDS) or on lead or

cadmium plated steel and other metals or coatings

which produce highly toxic fumes, keep exposure as

low as possible and below Threshold Limit Values (TLV)

using local exhaust or mechanical ventilation. In

confined spaces or in some circumstances, outdoors, a

respirator may be required. Additional precautions are

also required when welding on galvanized steel.

5.b.

Do not weld in locations near chlorinated hydrocarbon

vapors

coming from degreasing, cleaning or spraying operations.

The heat and rays of the arc can react with solvent vapors

form phosgene, a highly toxic gas, and other irritating

products.

5.c. Shielding gases used for arc welding can displace air and

cause injury or death. Always use enough ventilation,

especially in confined areas, to insure breathing air is safe.

5.d. Read and understand the manufacturer’s instructions for this

equipment and the consumables to be used, including the

material safety data sheet (MSDS) and follow your

employer’s safety practices. MSDS forms are available from

your welding distributor or from the manufacturer.

5.e. Also see item 1.b.

Mar ‘95

FOR ELECTRICALLY

powered equipment.

8.a. Turn off input power using the disconnect

switch at the fuse box before working on

the equipment.

8.b. Install equipment in accordance with the U.S. National

Electrical Code, all local codes and the manufacturer’s

recommendations.

8.c. Ground the equipment in accordance with the U.S. National

Electrical Code and the manufacturer’s recommendations.

CYLINDER may explode

if damaged.

7.a. Use only compressed gas cylinders

containing the correct shielding gas for the

process used and properly operating

regulators designed for the gas and

pressure used. All hoses, fittings, etc. should be suitable for

the application and maintained in good condition.

7.b. Always keep cylinders in an upright position securely

chained to an undercarriage or fixed support.

7.c. Cylinders should be located:

• Away from areas where they may be struck or subjected to

physical damage.

• A safe distance from arc welding or cutting operations and

any other source of heat, sparks, or flame.

7.d. Never allow the electrode, electrode holder or any other

electrically “hot” parts to touch a cylinder.

7.e. Keep your head and face away from the cylinder valve outlet

when opening the cylinder valve.

7.f. Valve protection caps should always be in place and hand

tight except when the cylinder is in use or connected for

use.

7.g. Read and follow the instructions on compressed gas

cylinders, associated equipment, and CGA publication P-l,

“Precautions for Safe Handling of Compressed Gases in

Cylinders,” available from the Compressed Gas Association

1235 Jefferson Davis Highway, Arlington, VA 22202.

iii

SAFETY

iii

Mar ‘95

WELDING SPARKS can

cause fire or explosion.

6.a.

Remove fire hazards from the welding area.

If this is not possible, cover them to prevent

the welding sparks from starting a fire.

Remember that welding sparks and hot

materials from welding can easily go through small cracks

and openings to adjacent areas. Avoid welding near

hydraulic lines. Have a fire extinguisher readily available.

6.b. Where compressed gases are to be used at the job site,

special precautions should be used to prevent hazardous

situations. Refer to “Safety in Welding and Cutting” (ANSI

Standard Z49.1) and the operating information for the

equipment being used.

6.c. When not welding, make certain no part of the electrode

circuit is touching the work or ground. Accidental contact

can cause overheating and create a fire hazard.

6.d. Do not heat, cut or weld tanks, drums or containers until the

proper steps have been taken to insure that such procedures

will not cause flammable or toxic vapors from substances

inside. They can cause an explosion even

though

they have

been “cleaned”. For information, purchase “Recommended

Safe Practices for the

Preparation

for Welding and Cutting of

Containers and Piping That Have Held Hazardous

Substances”, AWS F4.1 from the American Welding Society

(see address above).

6.e. Vent hollow castings or containers before heating, cutting or

welding. They may explode.

6.f.

Sparks and spatter are thrown from the welding arc. Wear oil

free protective garments such as leather gloves, heavy shirt,

cuffless trousers, high shoes and a cap over your hair. Wear

ear plugs when welding out of position or in confined places.

Always wear safety glasses with side shields when in a

welding area.

6.g. Connect the work cable to the work as close to the welding

area as practical. Work cables connected to the building

framework or other locations away from the welding area

increase the possibility of the welding current passing

through lifting chains, crane cables or other alternate cir-

cuits. This can create fire hazards or overheat lifting chains

or cables until they fail.

6.h. Also see item 1.c.

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Thank You

for selecting a QUALITY product by Lincoln Electric. We want you

to take pride in operating this Lincoln Electric Company product

••• as much pride as we have in bringing this product to you!

Read this Operators Manual completely before attempting to use this equipment. Save this manual and keep it

handy for quick reference. Pay particular attention to the safety instructions we have provided for your protection.

The level of seriousness to be applied to each is explained below:

WARNING

This statement appears where the information must be followed exactly to avoid serious personal injury or

loss of life.

This statement appears where the information must be followed to avoid minor personal injury or damage to

this equipment.

CAUTION

Please Examine Carton and Equipment For Damage Immediately

When this equipment is shipped, title passes to the purchaser upon receipt by the carrier. Consequently, Claims

for material damaged in shipment must be made by the purchaser against the transportation company at the

time the shipment is received.

Please record your equipment identification information below for future reference. This information can be

found on your machine nameplate.

Product _________________________________________________________________________________

Model Number ___________________________________________________________________________

Code Number or Date Code_________________________________________________________________

Serial Number____________________________________________________________________________

Date Purchased___________________________________________________________________________

Where Purchased_________________________________________________________________________

Whenever you request replacement parts or information on this equipment, always supply the information you

have recorded above. The code number is especially important when identifying the correct replacement parts.

On-Line Product Registration

- Register your machine with Lincoln Electric either via fax or over the Internet.

• For faxing: Complete the form on the back of the warranty statement included in the literature packet

accompanying this machine and fax the form per the instructions printed on it.

• For On-Line Registration: Go to our

WEB SITE at www.lincolnelectric.com. Choose “Quick Links” and then

“Product Registration”. Please complete the form and submit your registration.

vivi

TABLE OF CONTENTS

Page

Installation.......................................................................................................................Section A

Technical Specifications.......................................................................................................A-1

General Description..............................................................................................................A-2

Design Summary..................................................................................................................A-2

Case Assembly ....................................................................................................................A-3

Consumables .......................................................................................................................A-3

Mounting Brackets................................................................................................................A-3

Liner Installation and Trimming Instructions.........................................................................A-4

Contact Tip and Gas Nozzle Installation ..............................................................................A-4

Connecting the Torch to the Welding Equipment.................................................................A-4

Water Cooling Equipment ....................................................................................................A-5

Mounting the Torch ..............................................................................................................A-6

Work Leads ..........................................................................................................................A-7

Seam Tracking .....................................................................................................................A-7

Welding with Multiple Tandem MIG Systems.......................................................................A-7

Wire Straighteners................................................................................................................A-7

Tail Gas Coverage ...............................................................................................................A-7

________________________________________________________________________________

Operation.........................................................................................................................Section B

Electrodes and Equipment ...................................................................................................B-1

Making a Weld......................................................................................................................B-1

Avoiding Wire Feeding Problems .........................................................................................B-1

Shielding Gas Delivery .........................................................................................................B-1

Air Blast Cleaning.................................................................................................................B-1

Nozzle Reaming Stations .....................................................................................................B-1

Anti-Spatter Spray ................................................................................................................B-1

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Accessories.....................................................................................................Section C

General Options / Accessories..............................................................................C-1

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Maintenance ....................................................................................................Section D

Safety Precautions ................................................................................................D-1

Maintenance..........................................................................................................D-1

Torch Shield Replacement ....................................................................................D-1

Contact Tip Replacement......................................................................................D-2

Liner Replacement ................................................................................................D-2

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Troubleshooting..............................................................................................Section E

Safety Precautions.................................................................................................E-1

How to Use Troubleshooting Guide.......................................................................E-1

Troubleshooting Guide...................................................................................E-2, E-3

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Parts List ..............................................................................................................P210-P

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A-1

INSTALLATION

TANDEM MIG TORCH

A-1

TECHNICAL SPECIFICATIONS - Tandem MIG Torch

Product Number

G3494-2, 2A

G3494-3, 3A

G3494-4, 4A

G3494-5, 5A

G3494-6, 6A

Gun Cable Length

4 ft (1.2 m)

6 ft (1.8 m)

8 ft (2.4 m)

10 ft (3.0 m)

12 ft (3.6m)

65 scfh (31 liters/min) minimum

.45 gal/min at 40 psi

(1700 ml/min at 2.7 bar)

Tandem MIG Torch Cable Length Availability

Shielding Gas Flow Rate

Water Cooling Flow Rate for each Power Cable

HEIGHT WIDTH DEPTH WEIGHT

17.54 in. 3.75 in. 4.5 in. (w/o bracket) 14.0 lbs (w/ 4 ft. cable)

445.5 mm 95.3 mm 114.3 mm (w/o bracket) 6.4 kg. (w/ 4 ft. cable)

PHYSICAL DIMENSIONS

.45 gal/min at 40 psi

(1700 ml/min at 2.7 bar)

Water cooling flow rate for nozzle/gas cable

0.035" to 5/64" (0.9 mm to 1.9 mm)

Lead Electrode size

0.035" to 5/64" (0.9 mm to 1.9 mm)

Trail Electrode size

100% at 450 amps per side / 900 amps Total

Maximum current draw per electrode 650 amp / 60% duty cycle

Duty Cycle

A-2

INSTALLATION

TANDEM MIG TORCH

A-2

GENERAL DESCRIPTION

The Tandem MIG torch delivers two wire electrodes to

the weld pool. The wires are insulated from each other

for the purpose of independent arc regulation. When

welding, the wires or arcs are oriented one behind the

other. The torch provides a small but rugged housing

for delivering the two wires and it provides secure

delivery of the shielding gas. Each side of the torch is

rated for 450 Amps, 100% duty cycle with argon mix

shielding gases.

The 900 amp Tandem MIG torches are supplied in

two different configurations, the G3494-2 thru -6, (sin-

gle gas delivery configuration) and the G3494-2A thru

-6A (dual gas delivery configuration). The G3494-2

thru -6 is configured to be used with .035"-.052" diam-

eter electrodes. Shielding gas delivery is by a single

gas hose that delivers gas to the torch body. Internal

to the torch body the gas is split and delivered to the

two gas diffusers.

The G3494-2A thru -6A model is configured for .035"-

5/64" diameter wires. The G3494-2A thru -6A design

provides larger volumes of gas for gas shielding of the

welding arcs and weld pool. Gas is delivered through

the two welding power cable assemblies of the

G3494-2A thru -6A; each assembly receives separate

shielding gas from the two separate wire feeder sole-

noids. The dual source of gas provides additional gas

volume needed for proper gas shielding of larger weld

pools.

The torch can be operated bi-directionally, or even as

a single wire torch as the need arises.

The Tandem MIG torch is not factory equipped with a

feeder end connector. Use a K489-7 Fast-Mate

adapter kit (see ACCESSORIES section) to attach the

torch to the feeders. A K1500-1 gun connector must

be installed in addition to the K489-7 Fast-Mate

adapter, when using a Power Feed 10R Wire Feeder.

Liners are not included with the torch and must be

ordered separately (see ACCESSORIES section).

The torch is suitable for welding with Lincoln solid wire

steel MIG wires and metal core electrodes, from .035"

to 5/64" (0.9 mm to 1.9 mm) diameter.

Argon based shielding gases are recommended.

100% CO

is not recommend because of the higher

spatter levels associated with the gas.

DESIGN SUMMARY

The case, internal components and cables are the

main sub-assemblies of the torch.

TORCH CASE

The case is made from several pieces fabricated from

aluminum. The aluminum parts offer rigidity, strength

and resistance to heat and spatter. The main housing

is drilled and tapped for easy mounting to fixturing

equipment. For automation and robotic applications,

the barrel of the torch is removable and replaceable

without having an effect upon the existing tool center

point.

INTERNAL ASSEMBLY

Figure 1 Internal Assembly

All of the internal components are over molded with a

high temperature epoxy material. The over molding

rigidly holds all the parts in place while simultaneously

insulating the sub-assemblies. Each "subgun" in the

torch is electrically isolated from all other components

and individually water cooled. Separate water cooling

circuits minimize corrosion from electrical or galvanic

action.

Each face on the subguns where the diffuser engages

the torch is milled at a precise angle. The angle helps

to keep the ends of the wires close together while

allowing the use of standard contact tips. The slight

bend also creates good electrical contact between the

wire electrode and the tip.

A-3

INSTALLATION

TANDEM MIG TORCH

A-3

CABLE ASSEMBLY

Three cable assemblies deliver the necessary power

and cooling fluids to the torch.

a) G3494-X Series:

Two of the cable assemblies supply power, wire and

water cooling to each side of the torch. The third

bundle is made up of the nozzle water cooling

hoses, the air blast line and the shielding gas line.

b) G3494-XA Series:

Two of the cable assemblies supply power, wire,

shielding gas and water cooling to each side of the

torch. The third bundle is made up of the nozzle

water cooling hoses and the air blast line.

Torch liners must be ordered separately (see ACCES-

SORIES section). Customers who choose to run with

different size wires in the lead and trail must use the

correct liner for each wire.

CONSUMABLES

Heavy duty contact tips (KP2020 and KP2021 series)

are recommended for all welding applications (see

ACCESSORIES section). Standard or tapered contact

tips should only be considered in special applications

operating at low power.

Use only Tandem MIG diffusers with the Tandem MIG

torch (see ACCESSORIES section). The Tandem

MIG diffusers feature a narrow profile that prevents

internal short circuits.

All of the gas nozzles (see ACCESSORIES section)

also feature internal water cooling to assure a long life

of the torch and nozzle. Water cooling of the nozzle

reduces spatter accumulation. Nozzles are available

for welding in locations where space is restricted while

other nozzles are suitable for high deposition welding.

Inside each nozzle is a shield to prevent spatter from

bridging from the diffusers to the nozzle wall. The

shield is made from a high temperature, glass-epoxy

composite, or ceramic high temperature glass.

MOUNTING BRACKETS

A bracket for mounting the torch to a robot is available

(see ACCESSORIES section). The bracket features

an insulating plate to electrically isolate the torch from

other equipment. The insulating plate also serves as

a breakaway piece in the event of a severe collision.

A-4

INSTALLATION

TANDEM MIG TORCH

A-4

LINER INSTALLATION AND

TRIMMING INSTRUCTIONS

a) Lay the torch and cable on a flat surface and

straighten the cables.

b) With a 12 mm open-end wrench, unscrew the nut

on the cable connector that restrains the liner.

Remove the nozzle, and then remove both dif-

fusers.

c) Remove the old liners.

d) Insert the new untrimmed liners into the connector

end of the cable. Be sure the liner is of the correct

size and type as stenciled on the liner bushing.

e) Screw the nut on to the cable connector. Snug,

but do not overtighten.

f) Be sure the cable is still straight, and then trim the

liner so that 0.3 inch (6.5mm) of the liner extends

past the end of the torch. Remove any burrs from

the end of the liner.

g) Screw the gas diffusers onto the torch and tighten.

CONTACT TIP AND GAS NOZZLE

INSTALLATION

a) Choose the correct size contact tip for the elec-

trode being used (wire size is stenciled on the side

of the contact tip) and screw it snugly into the gas

diffuser.

b) Select the gas nozzle that best suits the welding

application. Inspect the o-rings on the nozzle for

cuts or tears, and replace if necessary. Examine

the nozzle shield and make sure it is free of spatter

and welding debris. Slide the nozzle onto the torch

and secure it into position with the threaded collar.

CONNECTING THE TORCH TO THE

WELDING EQUIPMENT

(See Figure 2)

There are three cable bundles for the Tandem MIG

torch.

a) G3494-X Series:

Two of the cable assemblies supply power, wire and

water cooling to each side of the torch. The third

bundle is made up of the nozzle water cooling

hoses, the air blast line and the shielding gas line.

b) G3494-XA Series:

Two of the cable assemblies supply power, wire,

shielding gas and water cooling to each side of the

torch. The third bundle is made up of the nozzle

water cooling hoses and the air blast line.

Both the G3494-X and the G3494-XA series torches

require a K489-7 Fast-Mate adapter to connect the

torch to wire feeder. When connecting to a Power

Feed 10R wire feeder a K1500-1 gun connector must

be installed at feeder before installing K489-7 Fast-

Mate adapter.

a) Check that the drive rolls and feeder guide tubes

are appropriate for the electrode size and type

being used.

CONNECTION DIAGRAM

For G3494-2 thru -6 and G3494-2A thru -6A

FIGURE 2

To Lead Water cooler

To Lead Wire Feeder

and Shielding Gas

Solenoid

To Trail Wire Feeder

and Shielding Gas

Solenoid

To Trail Wire Feeder

To Trail Water cooler

To Shielding Gas

No Hose

To Air Blast

To Nozzle Water cooler

G3494-2 thru -6

G3494-2A thru -6A

A-5

INSTALLATION

TANDEM MIG TORCH

A-5

b) Push the end connector from torch into K489-7

Fast-Mate adapter on the wire feeder, and then

tighten the locking nut. Do this for both of the torch

power cables.

c) Attach the water lines from the torch power cables

to a supply of cooling water.

d) Connect the water lines from the nozzle bundle to

the Tandem MIG interface. If a Tandem MIG

interface is not used, connect the water lines

directly to the water cooler or other type of con-

troller.

e) For G3494-X Series:

Connect the shielding gas line from the nozzle

bundle to the Tandem MIG interface. Alternatively,

connect the shielding gas line to the lead wire

feeder. Do not connect the shielding gas line to

trail wire feeder, because there would be no shield-

ing gas in the event of a delayed trail arc start .

For G3494-XA Series:

Shielding gas connection was completed in step b,

when torch cables were connected to Fast-Mate

connector. Check gas hose connection from wire

feeder solenoid to Fast-Mate connector for both

the lead and trail wire feeders.

f) Attach the air blast line to the high pressure dry air

supply (50-100 psi).

Water Cooling Equipment

FIGURE 3

WATER COOLING EQUIPMENT

(See Figure 3)

The Tandem MIG torch requires three separate water

coolers for proper cooling of the torch. The lead and

trail part of the torch each require a water cooler as

well as a third cooler for the nozzle. The three coolers

maintain proper temperatures in the torch even at

maximum rated output and duty cycle, leading to long

parts life and consistent welds. The separate coolers

eliminate the risk of any current leakage through the

water.

The water cooler for the nozzle should be pro-

grammed to turn on only during welding and remain

on for twenty seconds after the weld is complete.

Automatic control of the cooler minimizes the risk of

an operator removing the nozzle and getting sprayed

by the cooling fluid.

To maximize the life of the water coolers, the coolers

for the lead and the trail part of the torch should turn

on during welding and remain on for 60 seconds after

the weld is complete.

Water cooler manufacturers often specify additives

such as fungicides or alkalides. Follow manufacturers

recommendations to achieve proper operation and

long lifetimes without clogging.

K1536-1 Flow sensors should be placed in the return

line of each water circuit. Use a KP1529-1 connector

kit to attach the flow sensors as needed.

A-6

INSTALLATION

TANDEM MIG TORCH

A-6

MOUNTING THE TORCH

Always insulate the torch from any equipment or

fixturing. Use M19190 Bracket Arm to Torch Body

Insulator if necessary. (See Figure 4, Torch mounting

dimensions)

Check to make sure the cables are free to flex and do

not get tangled or caught on other equipment. Do not

let the cables drag on moving or hot parts.

Use a collision sensor if there is a risk that the torch

may impact an object when the torch or work piece

moves.

The case of the torch has holes drilled on the back,

left and right sides for mounting the insulator on either

the back or side of the torch. All of the holes are

drilled and tapped for #10-24x.50 screws.

Torch Mounting Dimensions

FIGURE 4

M19190

WIRE STRAIGHTENERS

Use a wire straightener with each wire drive. Failure

to use a wire straightener may result in inconsis-

tent welds and weld bead placement.

TAIL GAS COVERAGE

The Tandem Mig process is capable of establishing

wide weld bead profiles at higher than usual travel

speeds. When performing large weldments at these

high travel speeds the weld pool may become unpro-

tected while cooling as the welding torch providing the

shielding gas travels faster than the pool cools. To

provide weld pool protection during these applications

it is recommended to use the trailing gas assembly

(M18408-5) to provide additional shielding.

A-7

INSTALLATION

TANDEM MIG TORCH

A-7

WORK LEAD

Minimize the length of the electrode and work lead

cables. Do not exceed 50 ft (15m) of combined elec-

trode and work lead length.

To make the work lead connection, run a properly

sized lead from the work connection on the power

source directly to the fixture. The ground connection

should be as close to the part to be welded as possi-

ble. Do not combine work leads from the lead and

trail power source. Each machine requires an indi-

vidual work lead to the welding fixture.

Do not tightly bundle the electrode leads or the

work leads together. Welding performance may

deteriorate.

SEAM TRACKING

Seam tracking is required if the joint position wanders

or varies from part to part. Most optical and mechani-

cal trackers are compatible with Tandem MIG. Check

the manufacturer’s specifications for the seam track-

ing equipment. Do not exceed the rated power limit for

the seam tracking unit.

Through-the-arc-seam-tracking (TAST) works with

Tandem MIG in the same manner as single wire

TAST. Perform the current sensing for TAST on the

lead electrode.

WELDING WITH MULTIPLE

TANDEM MIG SYSTEMS

Special care must be taken when more than one

Tandem MIG torch is welding simultaneously on a sin-

gle part. Arc blow and arc interference may occur or

be magnified.

Every torch requires a separate shielding gas regula-

tor for proper flow rate and shielding gas coverage.

Do not attempt to supply shielding gas for two or

more torches from only one regulator.

Use one work lead per power source to connect the

work stud to the welding fixture. Do not combine all

of the work leads into one lead. Performing welding

in the direction away from the work leads. For exam-

ple, if there are two Tandem MIG systems welding on

the same part, there should be four work leads (two

lead and two trail power sources.)

B-1

OPERATION

TANDEM MIG TORCH

B-1

ELECTRODES AND EQUIPMENT

TheTandem MIG torch has been designed for use

with 0.035" through 5/64" (0.9 mm to 1.9 mm) Lincoln

solid steel MIG wires and metal core wires. Refer to

the appropriate Lincoln Process and Procedure

Guidelines for further information on welding settings.

MAKING A WELD

• When using an open arc process, it is

necessary to use correct eye, head

and body protection.

------------------------------------------------------------------------

a) Check to make sure the welding power sources

are turned on and set to the correct parameters

and programs.

b) Verify that the shielding gas supply is on and set

for the correct flow rate.

c) Set the preflow and postflow times the same on

both wire feeders. Make sure the post flow is long

enough to provide shielding during any crater fill

operation.

d) Check that all of the water coolers are operating

properly.

e) If applicable, make sure the Air-Blast spray sys-

tem is on.

f) Position the torch over the joint.

• Automatic equipment may start unexpectedly.

------------------------------------------------------------------------

g) Make a weld by sending a trigger signal to the

welding power sources.

AVOIDING WIRE FEEDING

PROBLEMS

Wire feeding problems can be avoided by observing the

following procedures:

a) Do not use a torch with cables longer than neces-

sary.

b) Do not kink or pull the cable around sharp corners.

c) Keep the cable as straight as possible when welding

or loading electrode through the cable.

d) Do not allow dolly wheels or trucks to run over

cables.

e) Use only clean, rust-free electrodes. Electrodes

manufactured by Lincoln Electric have proper surface

lubrication.

f) Replace the contact tips when the arcs start to

become unstable or the contact tip ends are fused or

deformed.

SHIELDING GAS DELIVERY

Adjust flow regulators for prescribed gas flow. Inspect

hoses regularly for worn or torn hoses. Perform a soapy

water test on hoses if a leak is suspected. Avoid kinking

or collapsing hoses with cable clamps. Insure that dif-

fuser is properly seated and tight. For G3494-XA series

torch, two gas sources are required. Do not attempt

to “Y” or Tee gas from one flow meter or regulator.

AIR BLAST CLEANING

The welding torch is equipped with a separate gas hose

for the purpose of providing a high pressure air blast

through the nozzle area to clear loose spatter that may

have accumulated between the two diffusers.

The high-pressure air is routed through the torch over

molded assembly and exits into the nozzle through an

opening in the nozzle shield. Air should be dry and free

of oil or anti- spatter compound. Pressure should be ade-

quate to free loose spatter (50-100 psi).

NOZZLE REAMING STATIONS

During robotic applications a reamer should be employed

to keep the nozzle clean. Reaming the nozzle between

welds will reduce the down time associated with manual

torch cleaning. The M18426-1 reaming station is an

option that is recommended for nozzle cleaning.

ANTI- SPATTER SPRAY

Anti-spatter compound may be used to keep weld spatter

from accumulating in the nozzle. Anti-spatter should not

be applied through the air blast line. Only dry air should

be used for air blast functions.

Anti-spatter may be applied to the interior of the nozzle

from an external sprayer. The M18426-1 reaming station

comes equipped with an external anti-spatter spraying

station.

Care should be taken to apply the right amount of anti-

spatter to the internal area of the nozzle. Too much anti -

spatter will cause diffuser clogging and weld porosity.

Only a very light covering of anti-spatter is required to

keep the spatter from cling to the nozzle.

WARNING

C-1

ACCESSORIES

C-1

GENERAL OPTIONS /

ACCESSORIES

The following options/accessories are available for

your Tandem MIG Torch from your local Lincoln

Distributor.

K489-7 Connector Kit - Magnum Fast-Mate

Adapter

Liners

Steel, Stainless and Metal Cored Electrodes

S24198-10 .035-.045" / 0.9-1.2mm, 9 ft.(2.7m)

S24198-12 .035-.045" / 0.9-1.2mm, 15 ft.(4.6m)

S24198-11 .052-.078" / 1.3-2.0mm, 9 ft.(2.7m)

S24198-13 .052-.078" / 1.3-2.0mm, 15 ft.(4.6m)

Diffusers

M19186 Diffuser

Contact Tip

Steel, Stainless and Metal Cored Electrodes

KP2020-7B1 .030” / 0.8mm

Contact Tips (Heavy Duty)

Steel, Stainless and Metal Cored Electrodes

KP2021-1B1 .035" / 0.9mm

KP2021-6B1 .040" / 1.0mm

KP2021-2B1 .045" / 1.2mm

KP2021-3B1 .052" / 1.3mm

KP2021-4B1 1/16" / 1.6mm

KP2021-5B1 5/64" / 2.0mm

Gas Nozzles

S24198-1 1 1/2” x 3/4” (37mm x 19mm)

contact tips recessed 1/8" (3mm)

S24198-2 1 1/2” x 3/4” (37mm x 19mm)

contact tips extended 1/8” (3mm)

S24198-3 1 1/2” x 7/8 (37mm x 22mm)

contact tips recessed 1/8" (3mm)

S24198-4 1 1/2” x 3/4” (37mm x 19mm)

15° bevel

S24198-5 1-5/8” x 1” (42mm x 24mm)

for reamers

S24198-6 1-5/8” x 1” (42mm x 24mm)

heavy duty

Nozzle Shields

M19267 Nozzle Shield (Fiber)

M19558 Nozzle Shield (Ceramic)

Torch Shields

S24432 Torch Shield(for G3494-X Torch, with

Air Blast)

S24432-1 Torch Shield(for G3494-X Torch,

Solid Shield)

S24432-A Torch Shield(for G3494-XA Torch,

with Air Blast)

S24432-A1 Torch Shield(for G3494-XA Torch,

Solid Shield)

Mounting Brackets

M19277 Bracket Arm

M19190 Bracket Arm to Torch Body Insulator

TANDEM MIG TORCH

D-1

MAINTENANCE

D-1

TORCH SHIELD REPLACEMENT

It is important that the torch shield be inspected and

replaced on a routine basis. The torch shields

(S24432, -1, -A, -1A) are designed to protect the more

expensive overmolded assembly of the Tandem torch

from arc and heat induced erosion. The shields must

be inspected and replaced on a routine basis. It is

important to replace burnt, eroded or other wise dam-

aged shields during a routine inspection process.

Care must be taken not to introduce moisture or fluid

between shield and the over molded assembly.

Retained moisture between the two components will

induce erosion of the overmolded assembly. When

replacing or inspecting the torch shield, clean compo-

nents free of oil, dirt and moisture before welding.

(See Figure 5)

a) Turn off power to the welding equipment.

b) Remove the nozzle from the torch.

c) Unscrew and remove the contact tips and dif-

fusers.

d) Using a 5/32" allen wrench, remove the four

screws holding the barrel clamp and then remove

the barrel clamp.

e) Slide the barrel off of the torch.

g) Remove the old torch shield from inside the barrel.

Place a new torch shield in the barrel, being sure

the orientation of the torch shield is correct. There

is a small step in the torch shield that seats in the

barrel. When assembled correctly, the face of the

torch shield will be flush with the end of the barrel.

h) Assembly of the remainder of the torch is the

reverse of the earlier steps.

FIGURE 5

Torch Shield Replacement

TANDEM MIG TORCH

SAFETY PRECAUTIONS

Have qualified personnel do the maintenance

work. If a problem cannot be corrected by

following the instructions, take the equipment to

the nearest Lincoln Field Service Shop for

repair.

-----------------------------------------------------------------------

ELECTRIC SHOCK can kill.

• Do not touch electrically live parts or

electrode with skin or wet clothing.

• Insulate yourself from work and

ground

• Always wear dry insulating gloves.

------------------------------------------------------------------------

See additional warning information

throughout this operator’s manual.

-----------------------------------------------------------

MAINTENANCE

a) Replace worn contact tips as required.

b) Remove spatter from inside of the gas nozzle and

from the tips after every 20 minutes of arc time, or

as required.

c) Replace the nozzle shield when it exhibits signs of

deterioration.

d) For steel or metal cored electrodes, clean the

cable liners after using approximately 2000 lbs of

electrode. Remove the cables from the wire

feeders and extend them so they are straight. Lay

the cables out on the floor, if possible. Remove

the contact tips from the torch. Using an air hose

and only partial pressure, gently blow out the

cable liners from the gas diffuser end. Flex the

cables over its entire length and again blow out

the cable. Repeat this procedure until no further

dirt comes out.

EXCESSIVE PRESSURE MAY CAUSE THE DIRT

TO FORM A PLUG.

-----------------------------------------------------------

WARNING

CAUTION

D-2

MAINTENANCE

D-2

CONTACT TIP REPLACEMENT

Each application will dictate the frequency of contact

tip replacement. Higher amperage higher duty cycle

operations will require more frequent contact tip

replacement. The condition of the contact tip greatly

effects the welding performance. A routine tip replace-

ment schedule should be established and adhered to.

For general operations contact tips should be

changed at the beginning of every shift.

LINER REPLACEMENT

Wire condition and plant environment as well as wire

consumption rate dictate how often a liner should be

changed. Smaller wire diameter will require a more

frequent change interval than large diameter opera-

tions. For general operations using .045" dia. wire lin-

ers should be changed after approximately 2000 lbs of

wire use.

TANDEM MIG TORCH

E-1

TROUBLESHOOTING

E-1

TANDEM MIG TORCH

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your

Local Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.

CAUTION

This Troubleshooting Guide is provided to help you

locate and repair possible machine malfunctions.

Simply follow the three-step procedure listed below.

Step 1. LOCATE PROBLEM (SYMPTOM).

Look under the column labeled “PROBLEM (SYMP-

TOMS)”. This column describes possible symptoms

that the machine may exhibit. Find the listing that

best describes the symptom that the machine is

exhibiting.

Step 2. POSSIBLE CAUSE.

The second column labeled “POSSIBLE CAUSE” lists

the obvious external possibilities that may contribute

to the machine symptom.

Step 3. RECOMMENDED COURSE OF ACTION

This column provides a course of action for the

Possible Cause, generally it states to contact your

local Lincoln Authorized Field Service Facility.

If you do not understand or are unable to perform the

Recommended Course of Action safely, contact your

local Lincoln Authorized Field Service Facility.

HOW TO USE TROUBLESHOOTING GUIDE

Service and Repair should only be performed by Lincoln Electric Factory Trained Personnel.

Unauthorized repairs performed on this equipment may result in danger to the technician and

machine operator and will invalidate your factory warranty. For your safety and to avoid Electrical

Shock, please observe all safety notes and precautions detailed throughout this manual.

__________________________________________________________________________

WARNING

E-2

TROUBLESHOOTING

E-2

TANDEM MIG TORCH

Observe all Safety Guidelines detailed throughout this manual

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your

Local Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.

CAUTION

PROBLEMS

(SYMPTOMS)

POSSIBLE

CAUSE

RECOMMENDED

COURSE OF ACTION

The drive rolls turn, but wire will not feed

or wire feeding is rough.

The arc starts, but during the weld the

arc goes out and wire keeps feeding.

Water leaks from the torch.

Porosity in the weld.

a. Gun cable is kinked and/or twisted.

b. Wire jammed in gun or cable.

c. Incorrect drive rolls and guide tubes.

d. Gun cable liner dirty.

e. Conduit clogged or dirty.

f. Worn drive rolls.

g. Electrode rusty or dirty.

h. Worn or improperly sized cable liner.

i. Partially flashed, melted or improper

contact tip.

a. Loose electrode or work lead connec-

tion.

b. The output of the Power Wave is

being exceeded, and the machine is

"phasing back".

c. The wrong weld program has been

selected.

a. Misassembled torch shield.

b. O-rings on the nozzle are cut, worn or

torn.

c. Loose connections where the cables

enter the torch.

a. The parts to be welded are dirty.

b. The parts to be welded have a surface

coating.

c. The arc length is excessively long.

d. Insufficient shielding gas flow.

e. Gas solenoid not turning on.

f. Loose shielding gas connections.

a. Keep as straight as possible. Inspect

cable and replace if necessary.

b. Remove wire from gun and cable,

then feed in new wire. Check for any

obstructions. Replace the liner if nec-

essary.

c. Be sure the wire diameter being used

matches the sizes of the drive rolls

and guide tubes.

d. Clean or replace liner.

e. Blow the conduit out with compressed

air. Check for obstructions. Replace

conduit if necessary.

f. Replace or reverse split drive rolls.

g. Replace the electrode.

h. Replace cable liner.

i. Replace the contact tip.

a. Verify that all the connections are tight

and are not overheating.

b. Change the welding procedure to

reduce the output current.

c. Make sure the welding program on the

power source matches the wire size

and gas actually being run.

a. Assemble the torch shield properly. It

should be flush with the bottom of the

barrel.

b. Replace the o-rings.

c. Properly connect the cables to the

torch.

a. Remove dirt, oil, lubricants and scale

from the part to be welded.

b. Do not weld painted, plated or insula-

tion-coated parts.

c. Properly set the weld procedure.

Generally arc lengths do not exceed

approximately 1/4".

d. Verify that the torch is being supplied

with 65 scfh.

e. Check that the gas solenoid fully turns

on during welding.

f. Check that all the connections are

sealed and that there are no cuts or

kinks in the shielding gas line.

E-3

TROUBLESHOOTING

E-3

TANDEM MIG TORCH

Observe all Safety Guidelines detailed throughout this manual

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your

Local Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.

CAUTION

PROBLEMS

(SYMPTOMS)

PPOSSIBLE

CAUSE

RECOMMENDED

COURSE OF ACTION

Porosity in the weld. (Continued)

The arc length is inconsistent.

There is arcing to the nozzle.

There is arcing between the contact tips

or arc flaring.

g. Wrong shielding gas composition.

h. Lead arc length too short.

i. Water is leaking into the arc.

j. Air is being drafted through the barrel.

k. Weld is too large.

l. Excessive anti-spatter fluid.

m. For installations with an anti-spatter

system, the anti-spatter solenoid may

not be closing completely.

n. For installations without an anti-spat-

ter system, the line may not be

plugged.

a. The contact tip is worn.

b. The liner and/or conduit are dirty or

worn.

c. The drive rolls and guide tubes on the

wire feeder are not properly assem-

bled.

d. The variation in the joint is too large.

e. The electrode or work lead connec-

tions are loose.

f. Only one ground lead is being used.

g. The wrong weld program has been

selected.

a. Spatter build-up is bridging between

the nozzle and contact tips or diffusers

b. The nozzle is too narrow for the appli-

cation.

c. The torch is not insulated from the fix-

ture.

a. Spatter build-up is creating a bridge

between the contact tips.

b. The wire size selection is wrong.

g. Make sure the shielding gas is appro-

priate for the weld procedure.

h. The lead arc should be in the spray or

pulse mode and not in globular or

short arc transfer.

i. Verify that nozzle to torch o-rings are

sealing properly.

j. Check that the o-rings to seal the bar-

rel to the over molded assembly are

sealing properly.

k. Use a trailing gas shield or a nozzle

that supplies a wider coverage of gas

shielding.

l. Use only a minimal amount of anti-

spatter fluid.

m. Verify that the solenoid closes com-

pletely.

n. Make sure the anti-spatter line is

plugged and sealed.

a. The wire should slide freely through

the contact tip. Replace if necessary.

b. Clean the liners and conduit. Replace

if necessary.

c. Make sure the correct size drive rolls

and guide tubes are in the feeder the

wire feeds through without distortion.

d. Improve fixturing and part forming if

necessary, or add seam tracking.

e. Verify that all the connections are tight

and are not overheating.

f. Use an individual ground lead from the

work stud of each power source to the

fixture.

g. Make sure the welding program on the

power source matches the wire size

and gas actually being run.

a. Remove spatter build-up on a regular

basis. Adjust weld procedure to

reduce spatter.

b. Switch to a wider nozzle.

c. Make sure the torch is on an insulated

mount. Use M19190 insulator if neces-

sary.

a. Remove spatter build-up on a regular

basis. Adjust procedure to reduce

spatter.

b. Switch to a larger diameter lead and

trail wire.

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Lincoln Electric Tandem MIG Torch Operating instructions

Brand: Lincoln Electric

Model: Tandem MIG Torch

Category: Welding System

Type: Operating instructions

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Lincoln Electric Tandem MIG Torch Operating instructions

Lincoln Electric Tandem MIG Torch Operating instructions

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